Liquid coffee concentrates

ABSTRACT

Improved liquid coffee concentrates that have furfuryl acetate to 4-ethyl guaiacol ratio values that approach the furfuryl acetate to 4-ethyl guaiacol ratio values of fresh brewed coffees brewed with the same coffees used to produce said coffee concentrates are disclosed. Methods of evaluating and adjusting a liquid coffee concentrate&#39;s furfuryl acetate to 4-ethyl guaiacol ratio value are also disclosed.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional ApplicationNo. 60/345,234, filed Oct. 19, 2001.

TECHNICAL FIELD

[0002] The present invention relates to liquid coffee concentrates,methods of producing and assessing the quality of liquid coffeeconcentrates and products containing said concentrates.

BACKGROUND OF THE INVENTION

[0003] Consumers produce the traditional “pot of coffee” by extractingthe desired components of roast and ground coffee using an automaticdrip coffee maker (ADC) or other form of brewer. Although the flavor andaroma of such a coffee beverage is highly desired and appreciated, theinconvenience of the brewing process has lead to the development ofinstant coffee and coffee concentrate products that allow the consumerto quickly make a single cup of coffee. Unfortunately, the productionprocesses used to produce such coffee products result in finishedproducts having ratios of flavor and aroma components that are differentfrom fresh brewed coffee. As a result, coffee beverages produced fromsuch concentrated products do not have the highly desired flavor andaroma of fresh brewed coffee.

[0004] Since the flavor and aroma of fresh brewed coffee is especiallydesired by consumers, attempts have been made to improve the flavor andaroma of products made from coffee concentrates. Such attempts includeincorporating volatile aroma flavor components into the finishedconcentrates, and the intensification of such components by theapplication of thermal energy. While such attempts are appreciated,there remains a need for a liquid coffee concentrate having the sameratios of flavor and aroma components as that of fresh brewed coffeebrewed from the same coffee used to produce the coffee concentrate.

SUMMARY OF THE INVENTION

[0005] Applicant's invention relates to a liquid coffee concentratehaving a furfuryl acetate to 4-ethyl guaiacol ratio value that is fromabout 50% to about 210% of the furfuryl acetate to 4-ethyl guaiacolratio value of fresh brewed coffee brewed with the same coffee used toproduce said coffee concentrate. Applicants also claim methods ofproducing and assessing the quality of coffee concentrates and productscontaining said concentrates.

DETAILED DESCRIPTION

[0006] A. Definitions

[0007] As used herein, the term “coffee product” includes, but is notlimited to coffee concentrates, coffee extracts and fresh brewed coffee.

[0008] As used herein, the term “coffee concentrate” means a coffeeextract that has undergone additional processing, such as thermaltreatment.

[0009] As used herein, the term “pyridine to 5-methyl-2-furfurylfuranratio value” refers to the number that is obtained when a coffeeproduct's pyridine and 5-methyl-2-furfurylfuran peak area values aredetermined according to Applicants' analytical test and said resultingpyridine's peak area value is divided by said 5-methyl-2-furfurylfuran'speak area value.

[0010] As used herein, the term “furfuryl acetate to 4-ethyl guaiacolratio value” refers to the number that is obtained when a coffeeproduct's furfuryl acetate and 4-ethyl guaiacol peak area values aredetermined according to Applicants' analytical test and said resultingfurfuryl acetate's peak area value is divided by said 4-ethyl guaiacol'speak area value.

[0011] As used herein, the term “unit operation” includes, but is notlimited to, equipment used to transfer heat such as heaters and coolers;holders; and transfer lines.

[0012] All percentages and ratios are calculated by weight unlessotherwise indicated.

[0013] As used herein, the articles a and an, when used in a claim, areunderstood to mean at least one of the components that are claimed ordescribed.

[0014] Publications, patents, and patent applications are referred tothroughout this disclosure. All references cited herein are herebyincorporated by reference in their entirety.

[0015] B. Coffee Concentrate Characteristics and Preparation

[0016] The quality of any ready-to-use coffee product, made from acoffee concentrate, is dependent on the properties of the concentrate.Although coffee concentrates contain innumerable aroma and flavorcomponents, Applicants discovered that the flavor and aroma of productsmade from concentrate approaches that of fresh brewed coffee when theconcentrate's ratio value of furfuryl acetate to 4-ethyl guaiacolapproaches the furfuryl acetate to 4-ethyl guaiacol ratio value of freshbrewed coffee brewed from the same coffee used to produce theconcentrate.

[0017] In addition to discovering the correlation between the ratiovalue of furfuryl acetate to 4-ethyl guaiacol, and flavor and aroma,Applicants discovered that a coffee concentrate's ratio of furfurylacetate to 4-ethyl guaiacol can be adjusted by the application ofthermal energy to the concentrate. While evaluating the suitability ofthermal processing, Applicants discovered that the entire, rather thanjust the hold tube portion, of a time and temperature profile must beconsidered. Applicants also recognized that the suitability of any setof thermal processing conditions is not only time and magnitudedependent but rate dependent as well. As a result, more common thermalprocessing descriptors such as Fo are insufficient to describe thethermal processing conditions that will result in the flavor and aromaimprovements of Applicants' invention. Thus, Applicants' processingconditions are described in terms of equivalent times and temperatures,as thermal processing conditions that are time, magnitude and ratedependent can be effectively and efficiently described by thesedescriptors.

[0018] A detailed description of Applicants' coffee concentrate andprocesses of making said concentrate is set forth in detail below.

[0019] 1. Coffee Concentrate

[0020] Embodiments of Applicants' coffee concentrate have a ratio valueof furfuryl acetate to 4-ethyl guaiacol that is from about 50% to about210% of the ratio value of furfuryl acetate to 4-ethyl guaiacol of freshbrewed coffee brewed with the same coffee used to produce said coffeeconcentrate. Other embodiments of Applicants' coffee concentrate have aratio value of furfuryl acetate to 4-ethyl guaiacol that is from about65% to about 150% of the ratio value of furfuryl acetate to 4-ethylguaiacol of fresh brewed coffee brewed with the same coffee used toproduce said coffee concentrate. Still other embodiments of Applicants'coffee concentrate have a ratio value of furfuryl acetate to 4-ethylguaiacol that is from about 80% to about 120% of the ratio value offurfuryl acetate to 4-ethyl guaiacol of fresh brewed coffee brewed withthe same coffee used to produce said coffee concentrate.

[0021] 2. Process of Making Coffee Concentrate

[0022] Coffee extracts that can be thermally processed according toApplicants' process can be prepared by any suitable process used toproduce a coffee extract. Preferably, said coffee extracts arenon-hydrolysed liquids having pyridine to 5-methyl-2-furfurylfuran ratiovalues of from about 3:1 to about 25:1 and solids contents of from about2.3% to about 25% by weight. Other preferred non-hydrolysed liquidcoffee extracts include those extracts having a pyridine to5-methyl-2-furfurylfuran ratio value of from about 4:1 to about 20:1 anda solids content of from about 3.5% to about 10% by weight; and thoseextracts having a pyridine to 5-methyl-2-furfurylfuran ratio value offrom about 4.5:1 to about 15:1 and a solids content of from about 3.5%to about 8% by weight.

[0023] Suitable methods of producing a coffee extract include, but arenot limited to, extracting said concentrate from roasted and ground,caffeinated or decaffeinated coffee using a continuous flow column. Saidcolumns are typically stainless steel vertical columns having aheight-to-diameter ratio greater than or equal to 6:1 and a perforatedtop and bottom retainer to permit the transport of feed water whilesimultaneously keeping coffee granules between the retainers. Suitablecolumns can be obtained from Niro A/S of Soeborg, Denmark.

[0024] Suitable extraction conditions include, but are not limited to,operating the extraction process at a temperature less than 149° C. andachieving a flow rate ratio of kilograms water per minute to kilogramsof coffee from about 0.1:1 to about 0.5:1, a water front speed of fromabout 5 cm to about 25 cm per minute, a draw-off ratio of mass ofextract to mass of coffee from about 4:1 to about 10:1; and a yield offrom about 17% to about 35%. Other suitable extraction conditionsinclude operating the extraction process at a temperature less than 149°C. and achieving a flow rate ratio of kilograms water per minute tokilograms of coffee from about 0.2:1 to about 0.4: 1, a water frontspeed of from about 12.5 cm to about 25 cm per minute, a draw-off ratioof mass of extract to mass of coffee from about 5.5:1 to about 8:1; anda yield of from about 17% to about 30%; and operating the extractionprocess at a temperature less than 149° C. and achieving a flow rateratio of kilograms water per minute to kilograms of coffee from about0.25:1 to about 0.36: 1, a water front speed of from about 12.5 cm toabout 15.2 cm per minute, a draw-off ratio of mass of extract to mass ofcoffee from about 6.5:1 to about 7:1; and a yield of from about 23% toabout 27.5%. Still other suitable extraction conditions includeoperating the extraction process at a temperature range of from about65° C. to about 99° C. or from about 82° C. to about 93° C. andachieving any set of flow rate, water front speed, draw-off ratio andyield parameters detailed previously.

[0025] After a suitable extract is obtained, said extract is thermallyprocessed. Suitable thermal processing equipment includes but is notlimited to, a MicroThermics model 25DH UHTIHTST unit. Said equipment canbe obtained from MicroThermics Inc. Raleigh, N.C. U.S.A. Regardless ofthe thermal processing equipment that is employed to thermally process acoffee extract, said equipment must be operated such that the extract isheat treated for an equivalent time from about 15 seconds to about 35seconds at an equivalent temperature of from about 115° C. to about 149°C.; preferably said equipment must be operated such that the extract isheat treated for an equivalent time from about 16.5 seconds to about 30seconds at an equivalent temperature of from about 126° C. to about 149°C.; and most preferably said equipment must be operated such that theextract is heat treated for an equivalent time from about 18 seconds toabout 28 seconds at an equivalent temperature of from about 137° C. toabout 149° C. Additionally, when an extract is heat treated for anequivalent time and temperature combination such that the followingmathematical relationship is true, the resulting concentrate issufficiently sterile to be aseptically packaged.${{Log}\left( {{Equivalent}\quad {Time}} \right)} \geq {{\log (10.1)} - \frac{\left( {{{Equivalent}\quad {Temperature}} - {135{^\circ}\quad {C.}}} \right)}{10.5}}$

[0026] The resultant coffee concentrate used may be used immediately, inthe same manner as conventional coffee concentrates, to form coffeecontaining products or may be packaged according to known methods forlater use.

Analytical Methods

[0027] 1. Method For Calculating Equivalent Time and Temperature

[0028] a.) Obtain time and temperature data for the thermal process ofinterest. This data must include at least 10 (time, temperature) datapoints for each unit operation that is part of said thermal process.

[0029] b.) Interpolate the time and temperature data obtained in Step(a) above using the Cubic Spline Interpolation Method found on pages143to 150 of Numerical Analysis, by Richard L. Burden, J. Douglas Faires,Sixth Edition, 1997 Brooks/Cole Publishing Company, ISBN 0-534-95532-0to obtain a time/temperature profile.

[0030] c.) Evaluate G_(Total) using the following equation and numericalintegration according to the Romberg Method found on pages 209 to 213 ofNumerical Analysis, Richard L. Burden, J. Douglas Faires, Sixth Edition,1997 Brooks/Cole Publishing Company, ISBN 0-534-95532-0:$G_{{Total}_{j}}:={\int_{0}^{{time}_{final}}{{\exp \left\lbrack \frac{{- 1} \cdot {Ea}_{j} \cdot 1000}{R \cdot \left( {{T_{emp}(t)} + 273.15} \right)} \right\rbrack}{dt}}}$

[0031]  for the following activation energies (Arrhenius model):

[0032]  Ea=(50, 70, 90, 110, 130, 150, 170, 190, 210, 230, 250, 270,290, 310, 330)

[0033]  Where said activation energies are expressed in kJ/mol, R=8.314J/mol. K, time is expressed in seconds and temperature is expressed in °C.

[0034] d.) Using the equation below:${\log \left( G_{Total} \right)} = {{\log \left( t_{E} \right)} - {\frac{1000}{{R \cdot l}\quad {{n(10)} \cdot T_{E}}} \cdot {Ea}}}$

[0035]  transform the (G_(Total), Ea) data points into a linearequation, and then use linear regression such that:

[0036]  Equivalent_Time:=10^(intercept(Ea, log(G) ^(_(Total)) ⁾⁾${Equivalent\_ Temperature}:={\frac{- 1000}{R \cdot {{ln}(10)} \cdot {{slope}\left( {{Ea},{\log\left( G_{Total} \right)}} \right)}} - 273.15}$

[0037]  where the Equivalent Time is expressed in seconds and theEquivalent Temperature in ° C.

[0038] 2. Method of Determining The Percent Solids of Fresh BrewedCoffee, Coffee Extracts and Coffee Concentrates (Analysis must be donein triplicate).

[0039] a.) Weigh a clean, empty vessel to the nearest 0.0001 gram.

[0040] b.) Place 25 ml of test sample in the vessel.

[0041] c.) Weigh the vessel containing the sample to the nearest 0.0001gram.

[0042] d.) Place the vessel in a convection oven at 105° C. and dry to aconstant weight.

[0043] e.) Remove the vessel from the oven and then weigh the vessel tothe nearest 0.0001 gram.

[0044] f.) Calculate % solids by weight as follows:${\% \quad {Solids}} = {\left\lbrack \frac{\left( {{DrySampleWeight} + {VesselWeight}} \right) - {VesselWeight}}{\left( {{InitialSampleWeight} + {VesselWeight}} \right) - {VesselWeight}} \right\rbrack \times 100}$

[0045] 3. Method of Preparing Fresh Brewed Coffee For Use In AnalyticalMethod No. 5 below.

[0046] Fresh brewed coffee is made using the same coffee used to producethe coffee concentrate of interest.

[0047] a.) Materials and Apparatus:

[0048] i.) 33.3 g of the roast and ground coffee having an averageparticle size of 600 to 850 microns.

[0049] ii.) 1420 mls of distilled water.

[0050] iii.) Mr. Coffee® model Accel™ automatic drip coffee brewer.

[0051] iv.) Mr. Coffee® Model # UF100 coffee filter.

[0052] b.) Brewing Procedure

[0053] i.) Place the coffee in a filter and then place the filter in thebrewer.

[0054] ii.) Pour the distilled water into the coffee brewer and thenbrew according to the Mr. Coffee® brewing directions.

[0055] iii.) After completing Step (b)(ii), separate the brewed coffeeinto 2 aliquots. Immediately freeze one aliquot, and use the secondaliquot to determine, according to Method No. 2 above, the % solids, byweight, of the coffee.

[0056] iv) Prior to testing according to Method No. 5 below, thaw thefrozen sample and dilute said sample to a concentration of 0.55% solidsby weight. After thawing and diluting the sample, the sample must beanalyzed according to Method No. 5 below within 30 minutes.

[0057] 4. Method of Preparing Coffee Extracts And Concentrates For UseIn Analytical Method No. 5 below.

[0058] a.) Within 30 minutes after an extract or concentrate isproduced, two aliquots of the extract or concentrate must be obtained.One aliquot is immediately packaged in a glass container that is thensealed and frozen. The % solids, by weight, of the second aliquot isimmediately determined according to Method No. 2 above.

[0059] b.) Prior to testing according to Method No. 5 below, thaw thefrozen sample and dilute said sample to a concentration of 0.55% solidsby weight. After thawing and diluting the sample, the sample must beanalyzed according to Method No. 5 below within 30 minutes.

[0060] 5. Method For Determining Furfuryl Acetate:4-ethyl Guaiacol RatioValues And Pyridine:5-Methyl-2-Furfurylfuran Ratio Values (Analysis MustBe Done In Triplicate).

[0061] Apparatus:

[0062] 1. 100 ml headspace sampling vial cleaned with distilled waterand heated in a muffle furnace at 500° C. for 24 hours.

[0063] 2. Thermostated container capable of being thermostated to atleast 5° C.

[0064] 3. Digital magnetic stirrer capable of a stirring speed of atleast 300 rpm.

[0065] 4. A clean 1 cm Twister™ bar having a coating thickness of 0.5 mm(stir bar coated with polydimethylsiloxane) supplied by the Gerstel GmbH& Co. KG of Mülheim an der Ruhr, Germany.

[0066] 5. A clean modified trap consisting of a 1-ml syringe barrel witha threaded glass tip packed with deactivated glass wool as described onpage 204 of S. Maeno and P. A. Rodriguez, “Simple and versatileinjection system for capillary gas chromatographic columns performanceevaluation of a system including mass spectrometric and light-pipeFourier-transform infrared detection”, J. Chromatogr. A 1996, 731,201-215.

[0067] 6. Gas Chromatograph (GC): Hewlett Packard (HP) model 6890: theGC is modified to accommodate the trap of (5) above as described on page203 of S. Maeno and P. A. Rodriguez, “Simple and versatile injectionsystem for capillary gas chromatographic columns performance evaluationof a system including mass spectrometric and light-pipeFourier-transform infrared detection”, J. Chromatogr. A 1996, 731,201-215.

[0068] 7. GC column: Durabond-5® Mass Spectrometer (30 meters in length,0.252 mm column ID and 1.0 μm film thickness) obtained from J&WScientific of Folsom, Calif., USA.

[0069] 8. Carrier gas, helium, capable of being delivered at a 2 ml/min.flow rate.

[0070] 9. Model HP 5973 Mass Selective Detector obtained from HewlettPackard, Santa Clarita, Calif., USA having a source temperature of about230° C., and a MS Quad temperature of about 150° C.

[0071] 10. Chemstation software obtained from Hewlett Packard, SantaClarita, Calif., USA and computer capable of running said software.

[0072] 11. MS spectral libraries of John Wiley & Sons and the NationalInstitute of Standards and Technology (NIST), purchased and licensedthrough Hewlett Packard.

[0073] Procedure:

[0074] 1. Thermostat the container (Apparatus # 2) to 5° C.

[0075] 2. Add 50 mls of the sample solution (prepared according toMethods 3 or 4 above) into the 100 ml headspace vial.

[0076] 3. Add 50 μls of an internal standard solution (2-heptanone, 500ppm in water) to the 100 ml headspace vial.

[0077] 4. Place the Twister™ bar into the 100 ml headspace vial and sealthe vial with a crimp seal.

[0078] 5. Place the 100 ml headspace vial from Step (4) above into thethermostated container

[0079] 6. Place the thermostated container containing the 100 mlheadspace vial on to the digital magnetic stirrer and stir at 300 rpmfor 45 minutes.

[0080] 7. After Step (6) above is completed, remove the Twister™ barfrom the 100 ml sample vial and rinse the bar with 4 mls of chilled (5°C.) Milli-Q™ water, and then blott the bar dry with Kimwipes™.

[0081] 8. After Step (7) above is completed place the Twister™ bar intothe trap (Apparatus 5).

[0082] 9. Start sequence of sample loading and analysis.

[0083] i) cool the pre-column to a temperature equal to or less than−90° C.

[0084] ii) next, connect the trap to a helium flow having a flow rate of15 ml/min

[0085] iii) then heat the trap to 200° C. for 8 minutes to desorb thetrapped flavor compounds.

[0086] 10. After Step (9) is complete, the GC-MS analysis is run asfollows. The following temperature program is used:

[0087] i) an initial temperature of 50° C. which is held for 1 minute,

[0088] ii) increase the initial temperature at a rate of 4° C./min untila temperature of 250° C. is reached,

[0089] iii) hold at 250° C. for 1 minute.

[0090] 11. Identify the peaks corresponding to furfuryl acetate, 4-ethylguaiacol, pyridine and 5-methyl-2-furfurylfuran using the MS spectrallibraries of John Wiley & Sons and the National Institute of Standardsand Technology (NIST), purchased and licensed through Hewlett Packard.

[0091] 12. Integrate the chromatographic peaks corresponding to the ions(listed below) for each identified compound using the Chemstationsoftware obtained from Hewlett Packard, Santa Clarita, Calif., USA.

[0092] i.) Pyridine (PYR) ion having a mass to charge ratio of 52

[0093] ii.) Furfuryl Acetate (FA) ion having a mass to charge ratio of140

[0094] iii.) 5-Methyl-2-Furfurylfuran (5MFF) ion having a mass to chargeratio of 162

[0095] iv.) 4-Ethyl Guaiacol (EG) ion having a mass to charge ratio of137

[0096] 13. For a test sample obtain the ratio values of furfuryl acetateto 4-ethyl guaiacol and pyridine to 5-methyl-2-furfurylfuran as follows:

[0097] i) ratio value of FA:EG=peak area FA ion/peak area EG ion

[0098] ii) ratio value of PYR:5MFF=peak area PYR ion /peak area 5MFF ion

REFERENCES

[0099] 1. E. Baltussen, P. Sandra, F. David and C. Cramers, “Stir BarSorptive Extraction (SBSE), a Novel Extraction Technique for AqueousSamples: Theory and Principles”, J. Microcolumn Separations, 11(10),737-747, 1999.

[0100] 6. Color Measurement (Analysis Must Be Done In Triplicate).

[0101] a.) Apparatus

[0102] i) Hunter D25L-9000 colorimeter with a DP9000 processor suppliedby Hunter Associates Laboratory Inc. of Reston, Va. U.S.A.

[0103] ii) Straight edge

[0104] iii) Aluminum sample cup 2.5 cm high and having an outsidediameter of 12.4 cm. The cup contains a cavity having a depth of 1.9 cmand an inside diameter of 11.8 cm.

[0105] b.) Procedure

[0106] i) Place a sufficient amount of coffee, having an averageparticle size of 600 to 850 microns, in the sample cup to overfill thesample cup.

[0107] ii) Level the coffee in the sample cup, using the straight edge,such that the coffee sample is uniformly even with the top of the cup.

[0108] iii) Place the cup in the Hunter D25L-9000 calorimeter andoperate the instrument according to the manufacturer's instructions.

[0109] iv) Record the L color value.

EXAMPLES

[0110] The following examples are illustrative of the present inventionbut are not meant to be limiting thereof.

Example 1

[0111] 3.9 Kg of an all Arabica coffee French roasted and ground isblended with 2.57 Kg of a French roasted and ground Arabica/Robustablend. This coffee is loaded into an extraction column about 6 inches indiameter and four and a half feet tall. The cap, which includes an exitport with a screen to contain the R&G coffee, is placed on the column.Nitrogen gas is used to flush air from the extraction system. Deaerateddistilled water heated to 82° C. is pumped counter-currently through thebed of coffee at about 1.9 liter/minute. 45.2 Kg of extract containing3.89% solids is obtained and cooled to about 29° C. This extract isfiltered through a 10 micron pleated glass filter cartridge to removesediment and then heat treated for an equivalent time of 21.2 seconds atan equivalent temperature of 145° C. using a MicroThermics model 25DHUHT/HTST unit to produce a concentrate.

[0112] Pre-thermal treatment and post thermal treatment samples of theconcentrate are tested according to Applicants' analytical methods. Thepre-thermal treatment sample is found to have a pyridine to5-methyl-2-furfurylfuran ratio value of 9.4, and the samples are foundto have ratio values of furfuryl acetate to 4-ethyl guaiacol listedbelow. Furfuryl Acetate:4-Ethyl Guaiacol Sample Ratio Value Fresh BrewedStandard 0.62 Pre-thermal treatment sample 1.75 Post thermal treatmentsample 0.60

Example 2

[0113] 3.6 Kg of an all Arabica roasted and ground coffee having roastcolor of 15.5 L is extracted as in Example 1 at a flow rate of about 1.8liters/minute, yielding 26 Kg of concentrate containing 3.59% solids.The extract is heat treated for an equivalent time of 26.5 seconds at anequivalent temperature of 141° C. using a MicroThermics model 25DHUHT/HTST unit to produce a concentrate.

[0114] Pre-thermal treatment and post thermal treatment samples of theconcentrate are tested according to Applicants' analytical methods. Thepre-thermal treatment sample is found to have a pyridine to5-Methyl-2-Furfurylfuran ratio value of 10.2, and the samples are foundto have ratio values of furfuryl acetate to 4-ethyl guaiacol listedbelow. Furfuryl Acetate:4-Ethyl Guaiacol Sample Ratio Value Fresh BrewedStandard 0.83 Pre-thermal treatment sample 3.06 Post thermal treatmentsample 1.44

Example 3

[0115] 6.64 Kg of a roasted and ground decaffeinated Arabica and Robustacoffee blend having roast color of 18.1 L is extracted as in Example 1at a flow rate of about 1.8 liters/minute, yielding 44.4 Kg of extractcontaining 3.56% solids. The extract is heat treated for an equivalenttime of 25.6 seconds at an equivalent temperature of 141° C. using aMicroThermics model 25DH UHT/HTST unit to produce a concentrate.

[0116] Pre-thermal treatment and post thermal treatment samples of theconcentrate are tested according to Applicants' analytical methods. Thepre-thermal treatment sample is found to have a pyridine to5-Methyl-2-Furfurylfuran ratio value of 12.7, and the samples are foundto have ratio values of furfuryl acetate to 4-ethyl guaiacol listedbelow. Furfuryl Acetate:4-Ethyl Guaiacol Sample Ratio Value Fresh BrewedStandard 0.47 Pre-thermal treatment sample 1.12 Post thermal treatmentsample 0.42

What is claimed:
 1. A coffee concentrate, said coffee concentrate beinga liquid and having a furfuryl acetate to 4-ethyl guaiacol ratio valuethat is from about 50% to about 210% of the furfuryl acetate to 4-ethylguaiacol ratio value of fresh brewed coffee brewed with the same coffeeused to produce said coffee concentrate.
 2. The coffee concentrate ofclaim 1 wherein said furfuryl acetate to 4-ethyl guaiacol ratio value isfrom about 65% to about 150% of the furfuryl acetate to 4-ethyl guaiacolratio value of fresh brewed coffee brewed with the same coffee used toproduce said coffee concentrate.
 3. The coffee concentrate of claim 2wherein said furfuryl acetate to 4-ethyl guaiacol ratio value is fromabout 80% to about 120% of furfuryl acetate to 4-ethyl guaiacol ratiovalue of fresh brewed coffee brewed with the same coffee used to producesaid coffee concentrate.
 4. A product comprising the coffee concentrateof claim
 1. 5. A product according to claim 4 wherein said coffeeconcentrate's furfuryl acetate to 4-ethyl guaiacol ratio value is fromabout 65% to about 150% of furfuryl acetate to 4-ethyl guaiacol ratiovalue of fresh brewed coffee brewed with the same coffee used to producesaid coffee concentrate.
 6. A product according to claim 4 wherein saidcoffee concentrate's furfuryl acetate to 4-ethyl guaiacol ratio value isfrom about 80% to about 120% of furfuryl acetate to 4-ethyl guaiacolratio value of fresh brewed coffee brewed with the same coffee used toproduce said coffee concentrate.
 7. A process for producing an improvedcoffee concentrate, said process comprising the steps of: a.) providinga liquid coffee extract; and b.) subjecting said liquid extract to heattreating for an equivalent time of from about 15 seconds to about 35seconds at an equivalent temperature of from about 115° C. to about 149°C.
 8. The process of claim 7 wherein said liquid extract is subjected toheat treating for an equivalent time of from about 16.5 seconds to about30 seconds at an equivalent temperature of from about 126° C. to about149° C.
 9. The process of claim 8 wherein said liquid extract issubjected to heat treating for an equivalent time of from about 18seconds to about 28 seconds at an equivalent temperature of from about137° C. to about 149° C.
 10. The process of claim 7 wherein said liquidextract is a non-hydrolysed liquid having a pyridine to5-methyl-2-furfurylfuran ratio value of from about 3:1 to about 25:1 anda solids content, by weight, of from about 2.3% to about 25%.
 11. Theprocess of claim 10 wherein said liquid extract is subjected to heattreating for an equivalent time of from about 16.5 seconds to about 30seconds at an equivalent temperature of from about 126° C. to about 149°C.
 12. The process of claim 11 wherein said liquid extract is subjectedto heat treating for an equivalent time of from about 18 seconds toabout 28 seconds at an equivalent temperature of from about 137° C. toabout 149° C.
 13. The process of claim 10 wherein said liquid extract isa non-hydrolysed liquid having a pyridine to 5-methyl-2-furfurylfuranratio value of from about 4:1 to about 20:1 and a solids content, byweight, of from about 3.5% to about 10%.
 14. The process of claim 13wherein said liquid extract is subjected to heat treating for anequivalent time of from about 16.5 seconds to about 30 seconds at anequivalent temperature of from about 126° C. to about 149° C.
 15. Theprocess of claim 14 wherein said liquid extract is subjected to heattreating for an equivalent time of from about 18 seconds to about 28seconds at an equivalent temperature of from about 137° C. to about 1490C.
 16. The process of claim 13 wherein said liquid extract is anon-hydrolysed liquid having a pyridine to 5-methyl-2-furfurylfuranratio value of from about 4.5:1 to about 15:1 and a solids content, byweight, of from about 3.5% to about 8%.
 17. The process of claim 16wherein said liquid extract is subjected to heat treating for anequivalent time of from about 16.5 seconds to about 30 seconds at anequivalent temperature of from about 126° C. to about 149° C.
 18. Theprocess of claim 17 wherein said liquid extract is subjected to heattreating for an equivalent time of from about 18 seconds to about 28seconds at an equivalent temperature of from about 137° C. to about 149°C.
 19. The process of claim 7 wherein the step of providing said liquidextract comprises producing a coffee extract using an extraction processthat is operated at: a.) a flow rate ratio of kilograms water per minuteto kilograms of coffee from about 0.1:1 to about 0.5:1; b.) a waterfront speed of from about 5 cm to about 25 cm per minute; c.) a draw-offratio of mass of extract to mass of coffee from about 4:1 to about 10:1;and d.) a yield of from about 17 to about 35%.
 20. The process of claim19, said process being operated at less than 149° C.
 21. The process ofclaim 20, said process being operated at a temperature of from about 65°C. to about 99° C.
 22. The process of claim 21, said process beingoperated at a temperature of from about 82° C. to about 93° C.
 23. Theprocess of claim 19, said processing being operated to achieve adraw-off ratio of mass of extract to mass of coffee from about 5.5:1 toabout 8: 1, and a yield of from about 17 to about 30%.
 24. The processof claim 23, said processing being operated to achieve a draw-off ratioof mass of extract to mass of coffee from about 6.5:1 to about 7:1, anda yield of from about 23 to about 27.5%.
 25. A method assessing thequality of a coffee concentrate, said method comprising the steps of:a.) providing a coffee concentrate; b.) providing a fresh brewed coffeebrewed from the same coffee used to produce the concentrate; and c.)determining the furfuryl acetate to 4-ethyl guaiacol ratio value of thecoffee concentrate and the furfuryl acetate to 4-ethyl guaiacol ratiovalue of the fresh brewed coffee.
 26. The method of claim 25, comprisingthe further step of comparing the furfuryl acetate to 4-ethyl guaiacolratio value of the coffee concentrate and the furfuryl acetate to4-ethyl guaiacol ratio value of the fresh brewed coffee.